东北黑土区横垄坡面融雪期细沟侵蚀特征研究

融雪期土壤由于受到融雪径流、冻融作用及未完全解冻层影响,细沟发育有别于降雨期。基于野外实地测量,对东北典型黑土区横垄坡面融雪期细沟侵蚀形态及空间分布进行分析。结果表明,横垄坡面融雪侵蚀产生的细沟主要为顺垄型、断垄型和复合型三种。顺垄型细沟平均长度和宽度较大,深度小于其他两种类型;断垄型细沟平均长度最小且变异程度最低、深度最大;复合型细沟平均长度最大、宽度最小。均匀坡面下部细沟侵蚀量最大,占坡面总量的85%,形态以顺垄型和断垄型细沟为主;坡面中部存在起伏区域,低洼处细沟侵蚀量最大,占坡面总量的64%,三种类型细沟均有发育。融雪期细沟发育的形态受微地形及未完全解冻层等因素影响,细沟分布则主要受坡位及融雪径流量等因素影响。

Rill Erosion Characteristics on Slope Farmland of Horizontal Ridge Tillage during Snow-melting Period in Black Soil Region of Northeast China

Rill development was different between thawing and rainfall periods,which was caused by the effects of snowmelt runoff,freezing-thawing action and incomplete thawing layer on soil.Based on the field observation,the study analyzed rill erosion morphology and its spatial distribution on slope land with horizontal ridge tillage in typical black soil area during snow melting period.The results showed that the rill on slope land with horizontal ridge tillage caused by snowmelt erosion were three types rill along the ridge,rill across the ridge and rill of complex morphology.Among the three types of rill,the average length and width of rill along the ridge were larger but the depth was less than that of the other two types.Length variation and the average length of rill across the ridge were the smallest but the depth was the largest.The average length of rill of complex morphology was the largest but the width was the smallest.The largest rill erosion mainly occurred in the lower position of uniform slope,accounting for 85％ of the whole slope,and the types mainly included rill along the ridge and rill across the ridge.Low-lying area in the middle position of slope with fluctuation had the largest rill erosion amount,accounting for 64％ of the whole slope,and rill erosion occurred in all the three types.On slope farmland of horizontal ridge tillage,changes of micro-topography and incompletely thawing layer affected rill morphology during thawing period,and rill distribution was mainly affected by slope topography and snowmelt runoff.